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(No Model.)

7 G. H. OOLE.

PLUG SWITCH EOE TELEPHONE AND TELEGRAPH CIRCUITS. No. 877,237, PatentedJan. 31, 1888.

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UNITED STATES PATE T OFFICE.

GEORGE H. COLE, OF ATLANTA, GEORGIA.

PLUG-SNITCH FOR TELEPHONE AND TELEGRAPH CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 377,237, dated January31, 1888.

A Application filed June 30, 1887. Serial No. 242,970. (No model.)

with another, or for altering any of the connections of a telephone ortelegraph line or circuit, which are termed plug-switches, and are madeof pieces of metal connected each to its appropriate wire or part ofcircuit, but

slightly separated from each other, so that the insertion of a plug orpin in the interval between them serves to make the connection.

The invention consists in the construction and arrangement of partshereinafter described and claimed.

In the accompanying drawings, Figure 1 is a sectional view of aplug-switch adapted specially for telephone switch-boards. Fig. 2 isanother form of plug-switch used upon telephone call-wire switch-boardsand telegraph switch-boards.

The reference-numeral 1 desgnates a telephone or telegraph switch-boardor other sup port upon which my improved plug'switch is mounted. Thelatter consists'of a metal tube, 2, which has a flange, 3, at one end,serving as a bearing on one side of the switch-board,

and also forming a slightly-flaring mouth to facilitate the insertion ofa plug or pin, The tube 2 extends partly through the board or base 1,and is held in place by a screw, 5, which runs from the rear side of theboard and enters a sleeve, 6, of hard rubber or other insulatingmaterial, inserted into the tube 2. This insulating-lining does notextend the entire length of the tube. The metallic screw or pin 5 passesthrough the tube 2 from the end thereofcontainingtheinsulating-lining,and its threads engagewith or press intosaid lining, so as to hold the parts together. The end of the screwpinis tapering and threadless and terminates within the unlined portion ofthe tube 2, so as to leave an interval or space between such pin and thetube 2. The headed end of the screw receives two metal washers, 8, whichrest upon the insulatingwasher 4, and between these metal washers 8 onelinewire, 9, or part of a circuit-wire is clamped, the other wire, 10,to be connected with the first, being passed through the switch-board land connected with the flanged end of the tube 2.

In order to connect one circuit with another, I make use of a splithollow plug, 11, which has a suitable knob or handle, 12, and isdesigned to be inserted into the flanged end of the tube 2, so as toslip onto the metal pin 5 and complete the metallic connection betweenthe same and the unlined portion of the tube 2. A switch of the typerepresented in Fig. l is particularly adapted for use upon telephoneswitchboards.

In the construction shown in Fig. 2 the parts already described are alsopresent, the only difference being in the manner of holding the tube inplace and mode of connecting or clamping the circuit-wires. Thescrew-threaded end 15 of the tube 2, projecting from the switch board,is in this modified form of switch made longer than in the other form,and receives a metallic nut, 16, which bears upon the base 1. Auinsulating washer or nut, 17, is placed upon the screw-threaded tube,and then two metal washers, 18, are retained by passing the screw-pin 5through the same so as to enter the insulating-lining.

One circuit-wire is, in the type shown in Fig. 2, wrapped around themetal tube, so as to be clamped by the metal nut 16, and the other wireis held between the metal washers 18. The split hollow insertible plugis also used in connection with the type of switch shown in Fig. 2,which, as has already been stated, is specially adapted for telephonecallwire switch boards and telegraph switchboards.

By the construction and arrangement of parts comprising a plug switch asabove described I attain greater simplicity and ease of operation thanin switches heretofore devised.

\Vhat I claim as my invention is 1. The combination, in a switch-plug,of the metal tube adapted to enter a switch-board, the tubularinsulating-lining arranged within one end of the metal tube, the headedpin passing through the insulating-lining beyond the same into the metaltube, the insulatingwasher on said pin, the metallic washers ar rangedon the pin, between the head thereof and the insulating-washer, and theinsertible hollow plug adapted to enter the metallic tube, substantiallyas described.

2. The combination, in a switch-plug, of the metal tube adapted to entera switch-board, a tubular insulating-lining arranged within one end ofsaid tube, a headed pin engaging and extending through the lining andextending beyond the latter into the tube, the insertible hollow plugadapted to enter the tube over the pin, a circuit-wire connected withthe tube beyond its lining, and a circuit-wire connected with theexternal end of the pin, substantially as described.

3. The combination, in a switch-plug, of the metal tube adapted to entera switch-board, a tubular insulating-lining arranged within one end ofthe tube, the headed pin extending through the tube into the latterbeyond the lining, the insertible hollow plug adapted to enter the tube,the insulating-washer on the pin, the metal. washers on the pin, betweenits head and the insulating-washer, a circuit-wire connected with thetube beyond the lining thereof, and a circuit-wire held between themetal washers on the pin, substantially as described.

4. The combination of the metal tube flanged at one end andscrew-threaded at the other and having an insulating-lining extendingpart of its length, the metal screw or pin, the metallic nut, theinsulating-washer, and the metallic washers, with a base or switchboard, circuitwires, and an insertible hollow plug adapted to connectthe metal pin with the tube, sub stantially as described.

In testimony whcreofl alfix my signature in presence of two witnesses.

GEO. I-l. COLE.

\Vitnesses:

WV. J. COLE, 'H. H. JA OKSO'N.

